Feed water regulator



Oct. 25, 1932. v. v. vEENscHoTEN FEED WATER REGULATOR Filed June 6. 1929 3 Sheets-Sheet l u *u N l mi! '1,' n' w N Il: l 'el' Q will( x I' w 'n Q s;

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Oct. 25, 1932.

v. v. vEENscHoTEN 1,884,930

ED WATER REGULATOR Filed June 6. 1929 3 Sheets-Sheet 2 o [EUCD Oct. 25, 1932. v. v. vEENscHoTEN FEED WATER REGULATOR Filed June 6, 1929 5 Sheets-Sheet 3 Patented Oct. 25, 1932 PATENT VINCENT V. VEENSCHOTEN, F ERIE, PENNSYLVANIA, ASSIGNOR T0 NORTHERN EQUIP- MENT COMPANY, OF ERIE, PENNSYLVANIA, A CORPORATION 0F PENNSYLVANIA FEED WATER REGULATOR Application led June 6,

of boilers operating under high pressures and capacities where load changes are frequent and material. The invention, however, is applicable to boilers operated otherwise. Another object of the invention is to provide suitable means for carrying out the method.

Other' objects of the invention will be apparent from a consideration of the accompanying drawings and the following description thereof.

Of the drawings, Fig. 1 is an elevation more or less diagrammatic of a boiler and water feeding apparatus therefor which einbody the features of my invention; Fig. 2 is an enlarged detail sectional view of a portion of the operating means of the feed water regulators of the system; and Fig. 3 is an elevation of a modified system of means for operatively connecting the feed water regulators with the feed water valve.

The method of feeding water to boilers which I have invented has for its object feeding Water to the boiler in proportion to the load on the boiler during the normal operation of the boiler. However, with boilers acting at high capacities or high steam pressures, particularly with materially var ing loads, material variations in the Water evel elevation in the boiler are produced by the 'eneration of steam which passes into the ody of the Water, and the expansion and contraction of this entrained steam. This effectdepends much on the intensity of the fire, the steam pressure, and the magnitude and rapidity of changes in load on the boiler, and other factors. Hence, it frequently happens that the water level elevation will materially vary even though the inflow of the water is substantially the same as the outflow of the steam. This also may be caused by the blowing down of the water in the boiler or by leakage or the like.

Hence, a further object of my invention is to prevent undue variations in the water level elevation, because of these various factors, and with this object I provide means for 1929. Serial No. 368,974.

maintaining substantially constant or within certain limits the Water level elevation in the boiler.

In providing apparatus for carrying out my method, I prefer to use thermostat regulators, but it will be understood that other types of regulators might be substituted for one or both of the regulators which I have illustrated and described. The type of therniostat regulator which I prefer to use is well known in the art under the trade naine of the Copes regulator, and it comprises an expansible thermostat in the nature of a inetallic tube which is mounted upon a suitable support. In this case, as part of the system, I employ a substantially vertical thermostatic tube 1() supported on bars 11. This regulator, however, could be mounted at any inclination. To avoid confusion, the bar 11 on the front of the tube 10 is not shown in Fig. 2. The upper end of the thermostat 10, in this case, is connected by a pipe 12 to the steam main 18 of the boiler system and, in this steam main, an orifice 14 is inserted, the diameter of the orifice being materially less than the diameter of the bore of the pipe 13. The lower end of the thermostat 10, in this case, is connected by pipes 15 and 16 to the water space of the boiler 17.

By this arrangement, it will be seen that the steam from the main has access to the thermostat through its upper end, and the Water of the boiler has access to the thermostat through its lower end. The central portion of the thermostat is mounted substantially at the same elevation as the average water level elevation in the boiler and, hence, the water in the thermostat is normally maintained at the same elevation as the water level in the boiler; and the rising and sinking of the water in the boiler causes contraction and expansion of the thermostat in an ordinary manner. However. in this instance, as the orifice 14 is between the boiler and the point of connection of the tube 12, the steam pressure in the thermostat will be somewhat lower than in the boiler and will vary with the variations in the load on the boiler. As a. consequence, the pressure of the steam in the thermostat 10 will vary with the load on the boiler, and the water elevation in the thermostat will also vary accordingly.

These variations in the elevation in the Water in the thermostat will vary the length of the thermostat by contraction and expansion and, as the upper end of the thermostat is fixed, the lower end will rise or sink accordingly.

The lower end of the thermostat is operatively connected with the feed water valve 18 by the following mechanism. A lever 19 is pivoted to the bar 11 at the point 20, and also to the lower end of the thermostat 10. As the thermostat varies in length, the lower end of the lever 19 will operate a slidably mounted bar 21. Upon this bar is fixed a rack 22 which coacts with the pinion 23 fixed to a cam 24. Associated with the cam, preferably by means of a roller 25, is a pivoted arm 26, and this arm, by means of a link 27, is pivotally connected with the lever 28. The lever 28 is pivotally connected by means of a link 29 with a lever 30. The lever 30 is adapted to operate the valve rod 31 of the valve 32. This valve is adapted to control the flow of water under pressure to and from a cylinder 33 by means of pipes 34 and 35. lVater under pressure is supplied to the pipe 34 and the pipe 35 is arranged to dispose of the water which flows from the cylinder 33. lVithin the cylinder 33 is a piston 36 which is arranged, by means of a rod 37, to operate the arm 38 and, hence, in an ordinary manner to operate the plunger 39 of the feed water valve 18.

It Will thus be seen that, in operation, as the load on the boiler is increased, the steam in the steam main at the point of connection of the pipe 12 will decrease in pressure, allowing the water in the thermostat 10 to rise somewhat, thus causing the thermostat to contract and to force the lower end of the lever 19 to the right. This, in turn, will operate the cam 24 and allow the arm 26 to sink, owing to the weight of the various mechan isms associated therewith, and this will cause the valve stem 3l to sink and allow water under pressure to flow through the port 40 into the lower end of the cylinder This will force the piston 3G upwardly and open further the valve 18, so that more water is free to flow into the boiler to compensate for the greater load on the boiler.

In order to suitably control the position of the plunger 39 and the valve 18. so as to avoid over-running of the plunger when the piston 36 is operated, I provide means for restoring the valve 32 to its normal position, so as to close the inlet ports 40 when the plunger has been moved sufficiently. The lever 30, instead of having a fixed fulcrum, has a floating fulcrum 41 which is fixed to the upper end of the piston rod 37. As the piston rod moves upwardly, for instance, it carries with it the fulcrum of the lever 30 and, thus,

moves the valve 32, so as Ato close the port 40. In practice, when the load change occurs, the valve allows only a slight amount of water to pass into the end of the cylinder 33 and this moves the piston of the plunger 39 a correspondingiy slight amount, depending upon the amount of variation in the load, and this slight movement of the piston is sufiicient to stop the flow of water into the cylinder.

By these means, it will be seen that the valve plunger is continuously maintained in a position to supply to the boiler amounts of water more or less proportional to the amount of steam flowing from the boiler. However, the drop in steam pressure through the orifice 14 in the steam main varies as the square of the load on the boiler varies, rather than exactly as the load varies. Hence, the varia-tion in elevation in the water in the thermostat 11 is proportional to the square of the change in load, and to correct for this, the cam 24 is used in order to provide changes in feed water valve opening proportional to the change in load. Obviously, the effective surface of the cam 24 can be varied to suit the needs. In this instance, I provide an effective surface which allows movement of the arms 26 proportional to the square root of the movement of the lower end of the thermostat 10, so that the movement of the arm will be proportional to the variation in load on the boiler. As a consequence, the movement of the valve plunger also will be proportional to the change in load.

It is desirable, however, to compensate also for the variations in drop in water pressure through the feed water valve when the position of the plunger is changed.

Opening the valve further will cause the drop in pressure through the valve to decrease and, hence, the changes in flow of water therethrough will not be proportional to the changes in valve opening. To comi pensate for this, I provide the control valve 5() having a plunger 51 which is operated in a. well-known manner, by means of a piston 52, or in any other suitable manner, so that, as the pressure through the valve 18 decreases, the plunger 51 will be opened more so as to compensate for this drop and bring the drop back to normal. This result is produced by having Ahe casing 53, which encloses the piston 52, communicating, by means of a pipe 54, with one side of the feed water valve 18 and, by means of an orifice 55, with the other side of the valve; so that the position of the piston 52 and, hence, of the plunger 51, will aol be changed so as to maintain constant the l drop through the valve 18.

As hereinabove explained, even though the inflow of water is equal to the outflow of steam, the water level in the boiler for various reasons will vary and sometimes inaterially. As a consequence, I provide some l? well-known means for varying the inflow of water to the boiler so as to maintain the water level elevation in the boiler substantially uniform or within some predetermined range. These means may comprise any well-known type of water level controlled feed water regulator. I prefer the thermostat 63 connected, by means of pipes 56 and 57, respectively, with the steam space and the water space of the boiler in an ordinary manner. The upper end of the thermostat is fixed to the support 58, and the lower end is pivotally connected with the lever 59 which has its fulcrum 60 pivoted to the support 58. The lever 59 is connected with the fulcrum 61 of the lever 28 by means of a link 62.

By this arrangement, it will be seen that, the water level rises in the boiler and in the thermostat, the thermostat will contract and elevate the link 62 and the fulcrum 61. This, in turn, will operate the valve 32 so as to allow water pressure to enter the cylinder 33 and close slightly more the feed water valve i8, thus compensating for the undesirable rise in level in the water in the boiler.

Although I have illustrated and described means for compensating for the drop in pressure through the feed water valve 18, yet, it is to be understood that other means may be provided for this purpose. I have found that this can be effectively provided for by increasing somewhat the action of the cam 24 on the valve. As has been explained hercin, 'die effective surface of the cam normally formed so that the movement of the arm 20 will be proportional to the variation of the load on the boiler. But, by increasing somewhat the inclination of the effective surface of the cam, provision may be made also for the drop in pressure through the valve caused by increasing the opening of the valve, sufiiciently to compensate for that drop and, thus, provide variations in flow through the valve equal to the variations in steam flow from the boiler.

Also, I have shown the steam controlled thermostat substantially vertical, but it should be understood that this thermostat may be inclined if desired, the inclination of the thermostat depending upon the amount of pressure drop through the orifice 14 and other conditions. If this drop is small, a long, inclined thermostat will be more effective than a vertical thermostat.

For certain installations, I have found it desirable to provide a modified system for controlling the feed of water to the boiler, according to my method. It is often desirable to have the means for operatively connecting the thermostats with the feed-water valve placed at a remote point, for convenience in inspection or otherwise and, partly with this in View, I have provided apparatus for carrying out my method which consists of a system of sylphon bellows operating, by means of long flexible tubes and electric wires, the feed water valve of the boiler so as to maintain the inflow equal to the outflow of the boiler.

This system is illustrated by Fig. 3 and it comprises the water level controlled thermostat and the steam controlled thermostat 71. These thermostats are operated respectively, as hereinabove described, by the water level variations in the boiler and the variations in the pressure drop through the orifice 72. And the levers 7 3 and 74, operated by the respective thermostats, are adapted to act on the movable ends and 7 6, respectively, of the sylphon bellows 77 and 78.

The bellows 77 is connected, by means of a tube 79, with a remote bellows 80. Any compression of the bellows 77 will result in a corresponding expansion of the bellows 80, it being understood that the bellows and the connecting pipe are filled with a suitable fluid for the purpose. The bellows 80, in turn, has its free end 81 connected with the arm 82 of the lever 83, the end 84 of the lever acting as its fulcrum.

With this arrangement, it will be seen that, as the water level in the thermostat 70 rises and the thermostat contracts, the sylphon bellows 77 will be compressed; and the bellows 80, expanding, will allow the arm 82 to sink. This will cause the electric contacts 85 to close and the electric current will flow from the supply wire 86 to the lever 87 and, thus, to the contacts 85 and to the solenoid 88 and back on the supply wire 89. The solenoid will close the contacts 90 and, by means of the supply wires 91, the electric motor 92 will be operated in the proper direction to close more the feed water valve 93. This operation will be brought about by means of the gear wheels 94 and the stem 95 which is threaded into the large gear wheel.

In case the water lowers in the thermostat 70, the reverse process will occur and the feed water valve will be opened more to supply the needed water to the boiler. It is to be understood that the end of each bellows to which the connecting tube is attached is the fixed end of the bellows. To further distinguish in this respect, the fixed end of each bellows is indicated by the heavy line and the free end by the light lines.

In order to prevent over-running of the valve in either direction, a sylphon bellows is provided. As the valve 93 is closed more by forcing in the valve stem 95, the bellows 100 will be expanded and this, in turn, will cause the contraction of the bellows 101 by means of the tube 102. The bellows 101 is arranged to act on the lever 87 and, thus, to force open the contacts 85 and, thus, prevent over-running of the valve.

When the increase in the drop in pressure through the orifice 72, owing to an increased load on the boiler, causes the' water in the thermostat 71 to rise, the lever 74 will compress the bellows 78. This, in turn, will eX- pand the bellows 105 and thus operate the cam 106. The effective surface of the cam is such as to elevate the fulcrum 84 of the lever 83 when the bellows 105 expands, and this will close the contacts 107. This, in turn, will cause the electric current to operate the solenoid 108 and close the circuit to the motor 92, so as to cause the motor to open further the valve 93 and supply the needed additional water to the boiler. Obviously, when the load on the boiler decreases, the reverse process will take place and the feed water valve will be properly controlled.

In this instance, I have provided an effective cam surface to the cam 106, not only to open the valve proportionately to the increase in load, but also to open it suliiciently to compensate for the drop in pressure through the valve as the valve opens, thus eliminating the necessity of the compensating valve 50 illustrated in Fig. 2. This, I accomplish by inclining the cam surface more than is required to change the valve opening proportional to the change in load. The amount of this excess inclination of the cam surface, necessary to compensate for the drop in pressure through the feed water valve, depends upon the special conditions, such as water pressure, pipe resistance, and other factors.

I claim as my invention:

1. In a boiler system a boiler having a feed water valve and a steam main, said main having a restricted orifice therein, a feed Water regulator comprising a thermostatic tube, one end of said tube being operatively connected with the water space of the boiler, the other end of the tube being operatively connected with said steam main with the orifice between the point of connection and the boiler, and means operatively connecting said thermostatic tube with said valve, said means comprising a cam arranged to vary the valve opening proportional to variations in load on the boiler.

2. In a boiler system as claimed in claim 1, means for maintaining uniform the pressure drop through said valve.

3. In a boiler system as claimed in claim 1, means depending on variations in the water level elevation in the boiler for additionally aecting the opening of said valve.

4. In a boiler system having a feed-water valve, the combination of means for varying the opening of said valve substantially proportional to variations in loads on the boiler, and means for maintaining substantially uniform the drop in pressure through said valve.

5. In a boiler system as claimed in claim 4, means depending on the water level in the boiler for varying the opening of said valve.

6. In a boiler system, a steam main and a feed water valve, a rst and a second sylphon bellows, a pipe thermostat with its respective ends operatively connected with said main and with said boiler, one end 0f said thermostat being fixed and the other end being operatively connected with the first sylphon bellows, said sylphon bellows being operatively connected with the second sylphon bellows, an electric motor, an electric circuit for operating said motor having a switch, means connecting said second sylphon bellows with said switch, and means connecting said motor with said valve, a third sylphon bellows operatively connected with said valve, and means operatively connecting said third bellows with said switch for opening said switch as said valve is operated.

In testimony whereof, I hereunto set my hand.

VINCENT V. VEENSCHOTEN. 

